3B0 121 321: Expansion tank cap for Volkswagen Passat B5

This expansion tank cap is designed for the Volkswagen Passat B5, in its 3B3 and 3B6 body versions equipped with the 2.0 131 bhp engine (engine reference ALT). It ensures the sealing of the cooling circuit by maintaining the pressure necessary for proper operation of the system. As part of the restoration or maintenance of a classic vehicle, replacing an aged or faulty cap is an essential step to prevent any engine overheating. This new part restores a level of reliability that meets original specifications.